<script setup lang="ts">
/* eslint-disable prefer-rest-params */
import type { CSSProperties } from 'vue'
import { computed, nextTick, ref, unref } from 'vue'
import {
  templateRef,
  tryOnMounted,
  tryOnUnmounted,
  useDebounceFn,
} from '@vueuse/core'
import * as utilsMethods from './utils'
const { animationFrame, copyObj } = utilsMethods
animationFrame()

interface SeamlessScrollProps {
  data: any[]
  classOption?: any
}

const props = defineProps<SeamlessScrollProps>()

const emit = defineEmits<{
  (e: 'scrollEnd'): void
}>()

const xPos = ref<number>(0)
const yPos = ref<number>(0)
const delay = ref<number>(0)
const height = ref<number>(0)
// 外容器宽度
const width = ref<number>(0)
// 内容实际宽度
const realBoxWidth = ref<number>(0)
const realBoxHeight = ref<number>(0)
const copyHtml = ref('')
// single 单步滚动的定时器
let singleWaitTime: any = null
// move动画的animationFrame定时器
let reqFrame: any = null
let startPos: any = null
// 记录touchStart时候的posY
let startPosY: any = null
// 记录touchStart时候的posX
let startPosX: any = null
// mouseenter mouseleave 控制scrollMove()的开关
let isHover = false
let ease = 'ease-in'

// eslint-disable-next-line vue/no-setup-props-destructure
const { classOption } = props

if (classOption.key === undefined)
  classOption.key = 0

const wrap = templateRef<HTMLElement | null>(`wrap${classOption.key}`, null)
const slotList = templateRef<HTMLElement | null>(
  `slotList${classOption.key}`,
  null,
)
const realBox = templateRef<HTMLElement | null>(
  `realBox${classOption.key}`,
  null,
)

const leftSwitchState = computed(() => {
  return unref(xPos) < 0
})

const rightSwitchState = computed(() => {
  return Math.abs(unref(xPos)) < unref(realBoxWidth) - unref(width)
})

const defaultOption = computed(() => {
  return {
    // 步长
    step: 1,
    // 启动无缝滚动最小数据数
    limitMoveNum: 5,
    // 是否启用鼠标hover控制
    hoverStop: true,
    // bottom 往下 top 往上(默认) left 向左 right 向右
    direction: 'top',
    // 开启移动端touch
    openTouch: true,
    // 单条数据高度有值hoverStop关闭
    singleHeight: 0,
    // 单条数据宽度有值hoverStop关闭
    singleWidth: 0,
    // 单步停止等待时间
    waitTime: 1000,
    switchOffset: 30,
    autoPlay: true,
    navigation: false,
    switchSingleStep: 134,
    switchDelay: 400,
    switchDisabledClass: 'disabled',
    // singleWidth/singleHeight 是否开启rem度量
    isSingleRemUnit: false,
  }
})

const options = computed(() => {
  // @ts-expect-error 此处为了解决ts类型检查不能解析的问题
  return copyObj({}, unref(defaultOption), classOption)
})

const leftSwitchClass = computed(() => {
  return unref(leftSwitchState) ? '' : unref(options).switchDisabledClass
})

const rightSwitchClass = computed(() => {
  return unref(rightSwitchState) ? '' : unref(options).switchDisabledClass
})

const leftSwitch = computed((): CSSProperties => {
  return {
    position: 'absolute',
    margin: `${unref(height) / 2}px 0 0 -${unref(options).switchOffset}px`,
    transform: 'translate(-100%,-50%)',
  }
})

const rightSwitch = computed((): CSSProperties => {
  return {
    position: 'absolute',
    margin: `${unref(height) / 2}px 0 0 ${
      unref(width) + unref(options).switchOffset
    }px`,
    transform: 'translateY(-50%)',
  }
})

const isHorizontal = computed(() => {
  return (
    unref(options).direction !== 'bottom' && unref(options).direction !== 'top'
  )
})

const float = computed((): CSSProperties => {
  return unref(isHorizontal)
    ? { float: 'left', overflow: 'hidden' }
    : { overflow: 'hidden' }
})

const pos = computed(() => {
  return {
    transform: `translate(${unref(xPos)}px,${unref(yPos)}px)`,
    transition: `all ${ease} ${unref(delay)}ms`,
    overflow: 'hidden',
  }
})

const navigation = computed(() => {
  return unref(options).navigation
})

const autoPlay = computed(() => {
  if (unref(navigation)) return false
  return unref(options).autoPlay
})

const scrollSwitch = computed(() => {
  // 从 props 解构出来的 属性 不再具有相应性.
  return props.data.length >= unref(options).limitMoveNum
})

const hoverStopSwitch = computed(() => {
  return unref(options).hoverStop && unref(autoPlay) && unref(scrollSwitch)
})

const canTouchScroll = computed(() => {
  return unref(options).openTouch
})

const baseFontSize = computed(() => {
  return unref(options).isSingleRemUnit
    ? parseInt(window.getComputedStyle(document.documentElement, null).fontSize)
    : 1
})

const realSingleStopWidth = computed(() => {
  return unref(options).singleWidth * unref(baseFontSize)
})

const realSingleStopHeight = computed(() => {
  return unref(options).singleHeight * unref(baseFontSize)
})

const step = computed(() => {
  let singleStep
  const step = unref(options).step
  if (unref(isHorizontal))
    singleStep = unref(realSingleStopWidth)

  else
    singleStep = unref(realSingleStopHeight)

  if (singleStep > 0 && singleStep % step > 0)
    throw new Error('如果设置了单步滚动，step需是单步大小的约数，否则无法保证单步滚动结束的位置是否准确')

  return step
})

function reset() {
  xPos.value = 0
  yPos.value = 0
  scrollCancle()
  scrollInitMove()
}

function leftSwitchClick() {
  if (!unref(leftSwitchState)) return
  // 小于单步距离
  if (Math.abs(unref(xPos)) < unref(options).switchSingleStep) {
    xPos.value = 0
    return
  }
  xPos.value += unref(options).switchSingleStep
}

function rightSwitchClick() {
  if (!unref(rightSwitchState)) return
  // 小于单步距离
  if (
    unref(realBoxWidth) - unref(width) + unref(xPos)
    < unref(options).switchSingleStep
  ) {
    xPos.value = unref(width) - unref(realBoxWidth)
    return
  }
  xPos.value -= unref(options).switchSingleStep
}

function scrollCancle() {
  cancelAnimationFrame(reqFrame || '')
}

function touchStart(e: any) {
  if (!unref(canTouchScroll)) return
  let timer
  // touches数组对象获得屏幕上所有的touch，取第一个touch
  const touch = e.targetTouches[0]
  const { waitTime, singleHeight, singleWidth } = unref(options)
  // 取第一个touch的坐标值
  startPos = {
    x: touch.pageX,
    y: touch.pageY,
  }
  // 记录touchStart时候的posY
  startPosY = unref(yPos)
  // 记录touchStart时候的posX
  startPosX = unref(xPos)
  if (!!singleHeight && !!singleWidth) {
    if (timer) clearTimeout(timer)
    timer = setTimeout(() => {
      scrollCancle()
    }, waitTime + 20)
  }
  else {
    scrollCancle()
  }
}

function touchMove(e: any) {
  // 当屏幕有多个touch或者页面被缩放过，就不执行move操作
  if (
    !unref(canTouchScroll)
    || e.targetTouches.length > 1
    || (e.scale && e.scale !== 1)
  )
    return
  const touch = e.targetTouches[0]
  const { direction } = unref(options)
  const endPos = {
    x: touch.pageX - startPos.x,
    y: touch.pageY - startPos.y,
  }
  // 阻止触摸事件的默认行为，即阻止滚屏
  e.preventDefault()
  // dir，1表示纵向滑动，0为横向滑动
  const dir = Math.abs(endPos.x) < Math.abs(endPos.y) ? 1 : 0
  if (
    (dir === 1 && direction === 'bottom')
    || (dir === 1 && direction === 'top')
  ) {
    // 表示纵向滑动 && 运动方向为上下
    yPos.value = startPosY + endPos.y
  }
  else if (
    (dir === 0 && direction === 'left')
    || (dir === 0 && direction === 'right')
  ) {
    // 为横向滑动 && 运动方向为左右
    xPos.value = startPosX + endPos.x
  }
}

function touchEnd() {
  if (!unref(canTouchScroll)) return
  let timer
  const direction = unref(options).direction
  delay.value = 50
  if (direction === 'top') {
    if (unref(yPos) > 0) yPos.value = 0
  }
  else if (direction === 'bottom') {
    const h = (unref(realBoxHeight) / 2) * -1
    if (unref(yPos) < h) yPos.value = h
  }
  else if (direction === 'left') {
    if (unref(xPos) > 0) xPos.value = 0
  }
  else if (direction === 'right') {
    const w = unref(realBoxWidth) * -1
    if (unref(xPos) < w) xPos.value = w
  }
  if (timer) clearTimeout(timer)
  timer = setTimeout(() => {
    delay.value = 0
    scrollMove()
  }, unref(delay))
}

function enter() {
  if (unref(hoverStopSwitch)) scrollStopMove()
}

function leave() {
  if (unref(hoverStopSwitch)) scrollStartMove()
}

function scrollMove() {
  // 鼠标移入时拦截scrollMove()
  if (isHover) return
  // 进入move立即先清除动画 防止频繁touchMove导致多动画同时进行
  // scrollCancle();
  reqFrame = requestAnimationFrame(() => {
    // 实际高度
    const h = unref(realBoxHeight) / 2
    // 宽度
    const w = unref(realBoxWidth) / 2
    const { direction, waitTime } = unref(options)
    if (direction === 'top') {
      // 上
      if (Math.abs(unref(yPos)) >= h) {
        emit('scrollEnd')
        yPos.value = 0
      }
      yPos.value -= step.value
    }
    else if (direction === 'bottom') {
      // 下
      if (unref(yPos) >= 0) {
        emit('scrollEnd')
        yPos.value = h * -1
      }
      yPos.value += step.value
    }
    else if (direction === 'left') {
      // 左
      if (Math.abs(unref(xPos)) >= w) {
        emit('scrollEnd')
        xPos.value = 0
      }
      xPos.value -= step.value
    }
    else if (direction === 'right') {
      // 右
      if (unref(xPos) >= 0) {
        emit('scrollEnd')
        xPos.value = w * -1
      }
      xPos.value += step.value
    }
    if (singleWaitTime) clearTimeout(singleWaitTime)
    if (unref(realSingleStopHeight)) {
      // 是否启动了单行暂停配置
      if (Math.abs(unref(yPos)) % unref(realSingleStopHeight) < unref(step)) {
        // 符合条件暂停waitTime
        singleWaitTime = setTimeout(() => {
          scrollMove()
        }, waitTime)
      }
      else {
        scrollMove()
      }
    }
    else if (unref(realSingleStopWidth)) {
      if (Math.abs(unref(xPos)) % unref(realSingleStopWidth) < unref(step)) {
        // 符合条件暂停waitTime
        singleWaitTime = setTimeout(() => {
          scrollMove()
        }, waitTime)
      }
      else {
        scrollMove()
      }
    }
    else {
      scrollMove()
    }
  })
}

watch(props.data, () => {
  copyHtml.value = unref(slotList)!.innerHTML
})

function scrollInitMove() {
  nextTick(() => {
    const { switchDelay } = unref(options)
    // 清空copy
    copyHtml.value = ''
    if (unref(isHorizontal)) {
      height.value = unref(wrap)!.offsetHeight
      width.value = unref(wrap)!.offsetWidth
      let slotListWidth = unref(slotList)!.offsetWidth
      // 水平滚动设置warp width
      if (unref(autoPlay)) {
        // 修正offsetWidth四舍五入
        slotListWidth = slotListWidth * 2 + 1
      }
      unref(realBox)!.style.width = `${slotListWidth}px`
      realBoxWidth.value = slotListWidth
    }

    if (unref(autoPlay)) {
      ease = 'ease-in'
      delay.value = 0
    }
    else {
      ease = 'linear'
      delay.value = switchDelay
      return
    }

    // 是否可以滚动判断
    if (unref(scrollSwitch)) {
      let timer
      if (timer) clearTimeout(timer)
      copyHtml.value = unref(slotList)!.innerHTML
      setTimeout(() => {
        realBoxHeight.value = unref(realBox)!.offsetHeight
        scrollMove()
      }, 0)
    }
    else {
      scrollCancle()
      yPos.value = xPos.value = 0
    }
  })
}

function scrollStartMove() {
  // 开启scrollMove
  isHover = false
  scrollMove()
}

function scrollStopMove() {
  // 关闭scrollMove
  isHover = true
  // 防止频频hover进出单步滚动,导致定时器乱掉
  if (singleWaitTime) clearTimeout(singleWaitTime)
  scrollCancle()
}

// 鼠标滚轮事件
function wheel(e: any) {
  e.preventDefault()
  if (
    unref(options).direction === 'left'
    || unref(options).direction === 'right'
  )
    return
  useDebounceFn(() => {
    e.deltaY > 0 ? (yPos.value -= step.value) : (yPos.value += step.value)
  }, 50)()
}

// watchEffect(() => {
//   const watchData = data;
//   if (!watchData) return;
//   nextTick(() => {
//     reset();
//   });

//   const watchAutoPlay = unref(autoPlay);
//   if (watchAutoPlay) {
//     reset();
//   } else {
//     scrollStopMove();
//   }
// });

tryOnMounted(() => {
  scrollInitMove()
})

tryOnUnmounted(() => {
  scrollCancle()
  clearTimeout(singleWaitTime)
})

defineExpose({
  reset,
})
</script>

<template>
  <div :ref="'wrap' + classOption['key']">
    <div
      v-if="navigation"
      :style="leftSwitch"
      :class="leftSwitchClass"
      @click="leftSwitchClick"
    >
      <slot name="left-switch" />
    </div>
    <div
      v-if="navigation"
      :style="rightSwitch"
      :class="rightSwitchClass"
      @click="rightSwitchClick"
    >
      <slot name="right-switch" />
    </div>
    <div
      :ref="'realBox' + classOption['key']"
      :style="pos"
      @mouseenter="enter"
      @mouseleave="leave"
      @touchstart="touchStart"
      @touchmove="touchMove"
      @touchend="touchEnd"
      @mousewheel="wheel"
    >
      <div :ref="'slotList' + classOption['key']" :style="float">
        <slot />
      </div>
      <div :style="float" v-html="copyHtml" />
    </div>
  </div>
</template>
